Desertification isA) a natural process of succession that cycles from deserts to prairies to forests to deserts. B) the formation of dryland ecosystems in regions where temperatures have increased. C) the natural movement of deserts advancing into new regions due to shifts in wind direction. D) often the result of topsoil erosion leading to a permanent reduction in productivity

Option (D)

Explanation:

Desertification is usually defined as the process that causes the top fertile soil to change into a complete desert area, due to high wind erosion, lack of rainfall, and also high temperature in that area.

This reduces the fertility of the soil and this affects the growth and productivity of the soil, thereby leads to the absence of vegetation and permanently destroys the soil.

Thus, the correct answer is option (D).